As methods for removing hazardous substances of microbe origin in the air such as viruses, bacteria, and the like, there are filtration using various kinds of filters, physical adhesion using adsorbents, and the like.
Japanese Patent Application Laid Open Publication No. 9-234317A discloses a virus removing filter using, as a virus-capturing body, at least one kind of sialic acid, a sialic acid derivative, and sugars, glycoproteins, and glycolipids containing the sialic acid and/or the sialic acid derivative. The publication mentions that this filter can be used in ordinary living space and efficiently removes viruses such as influenza viruses.
Japanese Patent Application Laid Open Publication No. 2001-527166A discloses a fibrous material including a plurality of interwoven threads with a high degree of microfibrillation wherein at least on thread is derivatised using cyanogen bromide to attach a natural receptor for a virus or a portion or an analogue thereof to capture a virus.
However, the methods for removing the hazardous substances in the air such as the filtration using a filter and the physical adhesion using an adsorbent are directed to capture of substances nonspecifically and have low precision. Further, in order to avoid re-floating of removed hazardous substances and to prevent multiplication of the hazardous substances so as not to allow them to serve as a new contaminant source, techniques for sterilizing and deactivating the hazardous substances must be incorporated.
Japanese Patent Application Laid Open Publication No. 8-333271A discloses an antiviral mask composed of a nonwoven fabric with which a tea extract is impregnated and ear stopper strings, wherein the nonwoven fabric with which the tea extract is impregnated is obtained in such a manner that the extract separated and refined from green tea components or black tea components is solved in purified water, is dehydrated lightly, and then, is dried. The publication mentions that this mask of the nonwoven fabric with which the tea extract is impregnate can be easily produced industrially, can maintain high virus trapping performance, can deactivate viruses, and can prevent re-entrainment of the viruses.